Excavator



Ap 1 40- J. P. WAITE 2,196,649

V 28 INVIENTOR JOHN P. IWAITE h; aw

ATTORNEYS 9, 1940. J, w rr 2,196,649

- EXCAVATOR Filed Aug. 4, 1938 2 Sheets-Sheet 2 FIGQ5.

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ACCUMULATOR I CYUNDER 5L 6 CONTROL VALVE IN'VENTOR' 'JOHN P.-WAITE ATTORNEYS PRESSURE I I REGULATOR v v I v BY SUMP Patented Apr. 9, 1940 I UNITED STATES PATENT OFFICE 'Johnl'almer Waite, Milwaukee, Wis.

Application August 4, 193a, Serial No. 222.900

- 1' Claim.

This invention appertains to excavators, and more particularly to a power-operated bucket excavating machine. 4

Much difliculty is experienced in excavating with power machinery, where the work is being done in confined places, such as behind the trees of a row of trees, which generally line the sidewalks of city streets.

It is, therefore, one of the primary objects of my invention to provide an excavator embodying a telescopic boom for the bucket, whereby the boom can be conveniently lowered in a collapsed position between the trees and then extended in rear of the trees to the desired point of excavating.

Another salient object of my invention is. to provide, a telescopic boom for excavating machines, with power means for automatically retracting and extending the boom. 1

A further object of my invention is to provide a telescopic boom for excavating machines embodying an inner section and an outer section sli'dably mounted on the inner section, with the inner section constructed as a complete cylinder for receiving a piston connected with the outer section, so that upon introduction of pressure in the inner section or cylinder of the boom on one side or the other of the piston, the boom can be extended or retracted as may be desired.

A still further object of my invention is to provide an excavating machine having a telescopic boom of the above character, which will be durable and eflicient in use, one that will be simple and easy to manufacture, and one which can be placed upon the market at a reasonable cost.

With these and other objects in view, the invention consists in the novel construction, atrangement, and formation of 'parts, as will be hereinafter more specifically described, claimed,

and illustrated in the accompanying drawings,

in which drawings:

Figure 1 is a fragmentary side elevational view of an excavating machine, showing my improved attachment incorporated therewith.

Figure 2 is a longitudinal sectional viewthrough the boom, taken substantially on the line 2-2 of Figure 1, looking in the direction of the arrows. H v

Figure 3 is an enlarged, fragmentary, detail, longitudinal sectional view through the boom, illustrating the construction of the cylinder head for the outer end of the inner boom section.

Figure 4 is an enlarged, detail, transverse sectional view through the boom, taken substantially on the line 4-4 of Figure 3, looking in the direction of the arrows.

Figure 5 is a transverse sectional view through the boom, taken on the line'i-J of Figure 2, looking in the direction of the arrows, illustrating 5 the means for anchoring the piston rod to the outer boom section.

Figure 6 is a detail sectional view taken on the line 6-6 of Figure 1, looking in the direction of the arrows, illustrating the means for mounting the clamshell bucket on the outer end of the boom.

Figure 7 is a diagrammatic view in top plan, illustrating one method of utilizing the excavator.

Figure 8 is a diagrammatic view of the hydraulic means employed for controlling and operating the piston.

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views, the letter E generally indicates a power excavator, which can be of any preferred character, size, or make. As illustrated, the excavator E includes the mobile base l0, upon which is rotatably mounted the cab ll containing the, operating ma- 2:; chinery. The mobile base iii, in the present instance, is shown to be of the crawler type, but,

obviously, wheels can be used in lieu thereof.

Hingedly mounted on one end of the cab is the mast 12 carrying a large sheave or pulley wheel ii at its upper end. The mast is connected by means of pulleys and cables with the brace frame I4, and the mast can be raised and lowered in any preferred manner.

Rockably mounted on the cab below the mast I2, as at I5, is my novel extensionboom IS. The

boom I6 is raised and lowered in the conventional manner, and thus the outer end thereof is provided with a cable H, which is trained over the large pulley wheel l3, carried by the machine. 40 The cable l'l then leads to the hoisting drums in.

the cab. a I

The extreme outer end of the boom carries a cross-pin or shaft I, on which is rockably mounted the head is for the clamshell bucket 20. 46 The clamshell bucket 20 is connected to the head l9 by means of a swivel connection 2|, whereby the clamshell bucket 20 can be rotated. The bucket is opened and closed in the conventional manner by a cable 22, which leads over a pulley 5o 23 carried by the cross-shaft'or pin l8. This cable 22 leads to the hoisting drums.

As stated, all of the above features are more or less in general use, and the same form no part of my present invention. is

. bucket 20, as described above.

The inner boom section 25 is formed in the nature of a cylinder, and, in fact, the. same forms a complete cylinder, and the opposite ends thereof are closed by cylinder heads 2] and 28. The cylinder head 23 is provided with a stufilng box 23, through which slidably extends a. piston rod 30. The inner end of the piston rod is connected with a piston 3|, which is slidabl,y m0unted within the cylinder or inner boom section. The outer end of the piston rod 30 is connected by means of a cross-pin 32 with the outer boom section 23.

By introducing pressure in the. outer end of the cylinder, the piston 3| will be caused to travel inward in the cylinder, and carry the sliding boom section 26 therewith. This will telescope $13. boom. By introducing pressure into the inher end of the cylinder, the piston 3| will be caused to travel to the outer end of the cylinder or boom section 25, and this will cause the extension of the boom.

The inner cylinder head 21 can be provided with a combined pressure and exhaust pipe 32, and the cylinder head 28 can be provided with a combined pressure and exhaust port 34. The port 34 communicates with a longitudinally extending pipe 35, which is mounted within a roove 36 formed in one side of the boom sec- 1151011 25. Air pressure can be utilized for operating the piston 3|, or hydraulic pressure can be 4 used. The use of hydraulic pressure may be Any preferred means can be utilized for -selectively introducing and exhausting pressure from the opposite ends of. the cylinder, and this means is preferably arranged within the cabin convenient control of the operator. In Figure 7, I have shown an excavator in the street alongside a row of trees. The boom is shown extended, and a comprehensive idea can be obtained as to how the bucket can be used in rear of the trees without damaging the trees in any way.

In Figure 8, -I have ?shown one conventional means for controlling the operation of the boom.

As illustrated. a four-way control valve is provided for governing the flow of fluid under pressure to one end of the cylinder, and the exhausting or return oi! the fluid to the pump. In the,

illustration, the valve is so set that the fluid under pressure is directed to the outer end of the cylinder, so that the piston will be forced inwardly. This will bring about the retraction of the boom. The fluid on the inner end of the cylinder is being returned to the intake side of the pump.

The bucket is free to rock longitudinally of the boom and transversely of the boom. The bucket can also rotate around a vertical axis. When the bucket swings transversely, the outer sleeve turns on the inner portion of the boom. As shown in Figure 2, the piston rod can rotate in the piston 3|; or, if so desired, the piston rod can turn in a ball-and-socket joint on the cross-pin 32.

Changes in details may be made without departing from the spirit or the scope of my invention, but what I claim as new is:

In an excavating machine, a mobile carriage, an extensible boom on the carriage including inner and outer sections, means pivotally connecting the inner end of the inner section to the carriage, a bucket carried by the outer end of the outer section, said inner section including'a tubular body and heads closing the opposite ends of the body forming a cylinder, and said outer section including a tubular body slidably mounted over the tubular body of the inner section for movement longitudinally thereof, a piston slidably mounted in said inner section, a piston rod extending out of the inner section and into the outer section, and means o'peratively connecting the rod to the outer section and to said piston, said inner section being provided with inlet and exhaust ports on opposite sides of the piston, as and for the purpose specified.

JOHN PALMER WAITE. 

